The issue I always have with my crop rotation is the space taken up by the brassicas. They are large, long-lived crops, and very valuable ones, and so they take up a lot of room. However, it's impossible to have a four-year rotation when one group of plants takes up half of your plot. I'm always trying to expand and build more beds, and it's largely the brassica issue that drives this. In theory expansion isn't a problem, as our plot extends to an acre in all. However, the soil is very poor indeed (a farmer friend described it, generously, as 'marginal'), and it floods, so conquering new ground is not simply a matter of digging it over, or laying down cardboard and compost. It involves building a raised bed and bringing in tons, literally, of manure or compost, along with having a major battle with the docks, nettles and hogweed already in residence.

This year I decided to make three new brassica beds over in my orchard, and give the main veggie garden a rest from growing them for a year. However, this didn't go to plan, largely because I haven't succeeded in taming the new ground. One of the new beds, despite its cardboard and manure layers, has been recolonised by silverweed, hogweed and nettles. The creeping roots of the nettles travel under the weedproof membrane quite a long distance from the hedge and pop up triumphant in the bed. Silverweed just seems to be immortal! The second bed is not too bad and has some caulis in it - as kind of plant canaries - and about half of them have survived the thriving rodent and slug populations so far. The third bed the one that I prepared first, putting down six inches of muck and covering with weedproof membrane over a year ago. Uncovering it to investigate, I found that the manure has totally disappeared, presumably taken into the hungry soil by worms, and the clay is baked hard just like before - hardly good planting material!

For this reason, two beds in the veggie garden did get used for early brassicas, and the winter plants just didn't get planted out of their modules. I potted them on instead, and then potted them on again. They are still in the greenhouse, asking to be potted on a third time, and big, healthy plants they are too. This means that the early rocket, pak choi, kohl rabi and calabrese are now being harvested, leaving these two beds available. I am also about to harvest the garlic, leaving another good bed available with no planned planting. While it has grown brassicas within the last 3 years, I may plant them there anyway while sorting out the new beds for next year. This land has never been cultivated before me and there are no veggie gardens in the vicinity, so the risk of diseases like club root is quite low so far.

This disaster, and others, have actually given me pause for thought in planning my brassicas, and how to save space with them. The first lesson is not to grow crops that will fail. Rocket sown in spring will just bolt, as will pak choi and kohl rabi unless sown at precisely the right moment. Similarly, last year I lost most of my winter caulis to frost, and they are just not worth the space they take up. This year I will grow them on in pots and plant them out into the polytunnel after the tomatoes come out. The second lesson is not to grow crops I won't eat. Last year a bed was taken up with swede and red cabbage that I just didn't get around to eating because there was always plenty of other veg that I like better. Not planting them means one whole bed saved. Finally, by potting young plants on rather than planting them out straight from the modules, I can plant them out after the early crops, or after lifting garlic or potatoes, and save even more space, the lesson being to plan where I plant the potatoes and garlic to be a brassica friendly spot.

As ever, it comes down to organization, thinking ahead and multidimensional planning in terms of space, succession, timing and the amount of a crop actually needed. Perhaps next year, with the three new beds finally clean and ready to go and improved organization, I will actually have a surplus of growing space for the first time ever!